The effects of metformin on insulin resistance and ovarian steroidogenesis in women with polycystic ovary syndrome

Role of insulin and insulin resistance in androgen excess disorders

Insulin has complex effects on cell growth, metabolism and differentiation, and these effects are mediated by a cell-surface bound receptor and eventually a cascade of intracellular signaling events. Among the several metabolic and growth-promoting effects of insulin, insulin resistance is defined as an attenuated effect of insulin on glucose metabolism, primarily the limited export of blood glucose into skeletal muscle and adipose tissue. On the other hand, not all the signaling pathways and insulin-responsive tissues are equally affected, and some effects other than the metabolic actions of insulin are overexpressed. Ovaries and the adrenal glands are two examples of tissues remaining sensitive to insulin actions where insulin may contribute to increased androgen secretion. Polycystic ovary syndrome (PCOS) is the most common form of androgen excess disorder (AED), and its pathogenesis is closely associated with insulin resistance. Patients with idiopathic hirsutism also exhibit insulin resistance, albeit lower than patients with PCOS. Although it is not as evident as in PCOS, patients with congenital adrenal hyperplasia may have insulin resistance, which may be further exacerbated with glucocorticoid overtreatment and obesity. Among patients with severe insulin resistance syndromes, irrespective of the type of disease, hyperinsulinemia promotes ovarian androgen synthesis independently of gonadotropins. It is highly debated in whom and how insulin resistance should be diagnosed and treated among patients with AEDs, including PCOS. It is not suitable to administer an insulin sensitizer relying on only some mathematical models used for estimating insulin resistance. Instead, the treatment decision should be based on the constellation of the signs, symptoms and presence of obesity; acanthosis nigricans; and some laboratory abnormalities such as impaired glucose tolerance and impaired fasting glucose.

Experts' opinion on inositols in treating polycystic ovary syndrome and non-insulin dependent diabetes mellitus: a further help for human reproduction and beyond

Introduction: This Experts' opinion provides an updated scientific support to gynecologists, obstetricians, endocrinologists, nutritionists, neurologists and general practitioners on the use of Inositols in the therapy of Polycystic Ovary Syndrome (PCOS) and non-insulin dependent (type 2) diabetes mellitus (NIDDM).Areas covered: This paper summarizes the physiology of Myo-Inositol (MI) and D-Chiro-Inositol (DCI), two important molecules present in human organisms, and their therapeutic role, also for treating infertility. Some deep differences between the physiological functions of MI and DCI, as well as their safety and intestinal absorption are discussed. Updates include new evidence on the efficacy exerted in PCOS by the 40:1 MI/DCI ratio, and the innovative approach based on alpha-lactalbumin to overcome the decreased therapeutic efficacy of Inositols in some patients.Expert opinion: The evidence suggests that MI, alone or with DCI in the 40:1 ratio, offers a promising treatment for PCOS and NIDDM. However, additional studies need to evaluate some still unresolved issues, such as the best MI/DCI ratio for treating NIDDM, the potential cost-effectiveness of reduced gonadotropins administration in IVF due to MI treatment, or the benefit of MI supplementation in ovulation induction with clomiphene citrate in PCOS patients.

Association between The Number of Retrieved Mature Oocytes and Insulin Resistance or Sensitivity in Infertile Women with Polycystic Ovary Syndrome

Background

The objective of this study was to describe the association between luteinizing hormone (LH)/ follicle-stimulating hormone (FSH) ratio and demographic variables and maturation stage of oocytes in insulin- resistant and insulin-sensitive patients with polycystic ovary syndrome (PCOS) in comparison with control group.

Materials and Methods

In this case-control study, 60 patients with in vitro fertilization (IVF)/intracytoplas- mic sperm injection (ICSI) indication were subdivided into 3 groups as follow: 20 subjects were assigned to control (fertile women with male infertility history) group, 20 subjects with PCOS were insulin resistant (IR) and 20 subjects with PCOS were insulin sensitive (IS). After puncture, retrieved oocytes were classified into metaphase II (MII) as mature and in metaphase I (MI) or germinal vesicle stage (GV) as immature. Regres- sion analyses were used to explore the association between MII oocyte number and demographic and clinical variables.

Results

LH/FSH ratio was significantly higher in PCOS-IR women compared to controls but not significantly dif- ferent from that of PCOS-IS group. PCOS-IR women had lower MII oocyte number compared with that of controls. According to multiple regression analysis, the number of previous assisted reproductive technology (ART) cycles was negatively associated with the number of MII oocytes.

Conclusion

Insulin resistance can be associated with reductions in MII oocyte number in patients with PCOS.

Polycystic ovarian syndrome: Assessment of approaches to diagnosis and cardiometabolic monitoring in UK primary care

INTRODUCTION

Polycystic ovarian syndrome (PCOS) is one of the commonest endocrine disorders affecting women of reproductive age. We examined the specific tests that are done in primary care to lead to the diagnosis of PCOS, and to support the diagnosis once made.

METHODS

One thousand seven hundred and ninety-seven women were identified from a pooled GP practice database. The search included all patients defined with PCOS or related terms. Records included demographic information, medical history (diagnoses), blood test results and whether a pelvic ultrasound scan had been performed.

RESULTS

The most common age of PCOS diagnosis was 20-29 years; 67.7% of the women had at least one concomitant Read-coded diagnosis. Most pelvic ultrasound scans were performed in the month immediately prior to diagnosis. In the 12 months prior to the diagnosis of PCOS being made, 30.5% of women underwent a measurement of their serum total testosterone level while 29.6% had their serum SHBG measured. For serum oestradiol, the corresponding statistics were 28.4%, LH 45.3% and for FSH 45.5% checked before diagnosis. Fasting blood glucose, random glucose and HbA1c were checked in 10.2%, 18.8% and 4.2%, of women before diagnosis, respectively, but in only 7.9%, 6.0% and 3.4% of women in the 24 months after diagnosis. There was a tendency for endocrine testing (oestradiol, LH, FSH, testosterone, SHBG) to peak in the weeks before diagnosis. For plasma glucose, testing was performed more evenly over time as for serum cholesterol. Of all women diagnosed with PCOS, 32.8% were prescribed metformin, 3.7% antihypertensives, 2.2% statins and 63.5% an oestrogen-containing contraceptive pill or HRT.

CONCLUSION

The underlying pathophysiology of PCOS is still not fully understood. As a result, treatment is often focused on individual symptoms, not the syndrome itself. Robust laboratory led protocols would provide the necessary information to enable an appropriate diagnostic evaluation/cardometabolic monitoring.

COMPARISON OF FINASTERIDE, METFORMIN, AND FINASTERIDE PLUS METFORMIN IN PCOS

The effects of finasteride on insulin resistance and of metformin on hyperandrogenism in patients with polycystic ovary syndrome (PCOS) are not clear. This study therefore compared the effects of finasteride, metformin, and finasteride plus metformin treatments on hormone levels, insulin resistance, and hirsutism score in women with PCOS. Fifty-two patients with PCOS were randomly assigned to receive finasteride 5 mg/day, metformin 1700 mg/day or finasteride plus metformin for 12 months. Body mass index (BMI), Ferriman Gallway score (FGS), serum concentrations of estradiol, sex hormone-binding globulin, free testosterone, dehydroepiandrosterone sulfate (DHEAS), androstenedione, and homeostasis model assessment of insulin resistance (HOMA-IR) index and areas under the curve (AUC) for insulin and glucose were evaluated before and after 12 months of treatment. Reductions in FGS, free testosterone, DHEAS, androstenedione, HOMA-IR, AUC-insulin, and AUC-glucose were significant within each group, whereas BMI and estradiol were not. Comparisons of changes in parameters in the 3 groups did not clearly show the superiority of any treatment modality. The treatment with finasteride alone significantly reduced both androgen levels and parameters of insulin resistance. In addition, metformin alone was effective, and not inferior to finasteride, in the treatment of hyperandrogenism.

Comparison of spironolactone and spironolactone plus metformin in the treatment of polycystic ovary syndrome

The aim of this study was to evaluate and compare the effects of spironolactone and spironolactone plus metformin treatments on body mass index (BMI), hirsutism score, hormone levels, and insulin resistance in women with polycystic ovary syndrome (PCOS). Thirty-seven patients with PCOS were randomly assigned to receive spironolactone 100 mg/d (spironolactone group, 18 patients) or spironolactone 100 mg/d plus metformin 2000 mg/d (combination group, 19 patients) for 12 months. BMI, modified Ferriman-Gallway score (FGS), serum levels of regarding hormones, and homeostasis model assessment of insulin resistance (HOMA-IR) index were assessed before and after the treatments. Six patients in the spironolactone group and four patients in the combination group reported inter-menstrual vaginal bleeding during treatments. In hirsutism scores, the spironolactone therapy resulted in 25.2% reduction, while combination therapy resulted in 28.3% reduction (p > 0.05, between groups). When the groups were compared in terms of percent changes in BMI, FGS, HOMA-IR, and hormone values other than free testosterone, no significant difference was noted. In the present study, FGSs were significantly decreased in both groups; however, combination therapy was not more effective than spironolactone alone in terms of BMI, FGS, hormone levels, or insulin resistance.

Metformin improves endothelial function and carotid intima media thickness in patients with PCOS

OBJECTIVE

Oral contraceptive pills (OCP) are widely used for treating women with polycystic ovary syndrome (PCOS). Metformin has beneficial effects on insulin resistance and endothelial functions. The aim of this study was to investigate the effects of treatment with drospirenone/ethinyl estradiol (EE) alone or in combination with metformin on the flow-mediated vasodilatation (FMD) and carotid intima media thickness (CIMT) in women with PCOS.

METHODS

Fifty women with PCOS (mean age 23 ± 5) were randomized to oral treatment of OCP alone (n = 25) or an OCP combination with metformin (n = 25) for 6 months. FMD from the brachial artery and CIMT were calculated. The hormonal profile, HOMA-IR score, basal insulin and glucose levels were studied in both groups. Before and after 6 months' treatment, echocardiographic measurements and laboratory tests were also obtained.

RESULTS

After 6 months' treatment we observed a small decrease in FMD in the OCP group (14.9 ± 9.4 versus 14.4 ± 9.9, p = 0.801) and a slight increase in the combination group (14.5 ± 9.1 versus 15.0 ± 8.0, p = 0.715) but neither of them reached significance. CIMT increased in the OCP group (0.048 ± 0.011 to 0.050 ± 0.010 cm, p = 0.433) and decreased slightly in the combination group (0.049 ± 0.012, 0.048 ± 0.011 cm, p = 0.833).

CONCLUSION

We demonstrated that adding metformin to OCP treatment may have beneficial effect on FMD and CIMT that represent vascular function in patients with PCOS. These results suggest that adding metformin to OCP treatment for PCOS could preserve the cardiovascular system and improve it.

The association of androgenetic alopecia and insulin resistance is independent of hyperandrogenemia: A case-control study

BACKGROUND/OBJECTIVES

Androgenetic alopecia (AGA) occurs due to the effect of androgens and genetic predisposition. The association between hyperandrogenism and insulin resistance (IR) has been clearly documented. In recent years there have been reports supporting the presence of IR in AGA. The study aimed to investigate the presence of IR in women with AGA and discern whether or not it is associated with hyperandrogenism.

METHODS

Overall, 77 women with AGA were included in the study. Patients with Ludwig grades I-III AGA were enrolled in the study. Blood samples were drawn for measurements of hormone profile, basal insulin and fasting blood glucose (FBG). An oral glucose tolerance test was performed on another day. IR was assessed by the homeostasis model assessment score.

RESULTS

All IR parameters were significantly higher in the 75 study subjects without DM than in the control group (P < 0.05). After excluding five patients with IGT, the level of all IR parameters were still higher than in the control group (P < 0.05). Hyperandrogenemia was found in 30 (40%) patients. When this second group (n = 45) (excluding patients with hyperandrogenemia) was compared with the control group on IR, all parameters except for basal insulin were significantly higher in the second group than in the controls (P < 0.05).

CONCLUSION

Our results suggest a relation between IR and AGA in female patients. We showed for the first time that the association of AGA and IR is independent of hyperandrogenemia.

Is metformin indicated as primary ovulation induction agent in women with PCOS? A systematic review and meta-analysis

BACKGROUND

A recent meta-analysis has proven that metformin (M) is highly effective for ovulation induction in the clomiphene citrate (CC)-resistant patient. There is uncertainty whether M should be introduced as a primary ovulation induction agent in polycystic ovarian syndrome (PCOS).

METHODS

We conducted a systematic review and meta-analysis to establish if M is better when given alone or in combination with CC (CC+M) when compared with CC alone. This systematic review studied live birth delivery rate as the primary outcome.

RESULTS

We identified 14 prospective trials. Analysis of these results showed a reduction in the live birth rate in the group of patients treated only with M when compared with CC alone (OR = 0.48, 95% CI 0.31-0.73, p = 0.0006). An increase in ovulation (OR = 1.6, 95% CI 1.2-2.1, p = 0.0009) and pregnancy rate (OR = 1.3, 95% CI 1.0-1.6, p = 0.05) with CC+M when compared with CC alone was reported, but no difference was found when live birth rate was analyzed (OR = 1.1, 95% CI 0.8-1.5, p = 0.61).

CONCLUSION

CC alone is superior to M alone regarding live birth rate and ovulation. The combination (CC+M) is superior to CC alone as a primary method for ovulation induction and to achieve pregnancy in PCOS. However, when addressing live birth rate, no statistically significant difference could be demonstrated. Because of the side effects profile and contraindications of M, we believe M should not be indicated as a primary ovulation induction agent in women with PCOS.

Diamel therapy in polycystic ovary syndrome reduces hyperinsulinaemia, insulin resistance, and hyperandrogenaemia

For to determine the effect of Diamel on the insulin resistance, insulin sensitivity, and sexual hormones results in women with polycystic ovary syndrome (PCOS). A study was carried out on 37 patients with this disorder. A triple-blind clinical trial was designed in which the Diamel food supplement was compared with a placebo. The women with reproductive ages were randomly distributed in two groups, with 18 and 19 women respectively, and they took Diamel or placebo and were followed up during 6 months with clinical and biochemical evaluation. A significant decrease in the HOMA-IR from the initial value at six months was observed in the group with Diamel. The insulin sensitivity improved considerably in this group. The rate of menstrual recovery was higher in the group with Diamel, and two patients from this group obtained pregnancy. The hormone levels shows a significant decrease in testosterone at 3 months in the group with Diamel compared with the control group. The LH also decreases in the same group when comparing the start with 6 months.We concluded that the Diamel decreases insulin resistance and improves sensitivity to this hormone in women with PCOS, with improvement in the levels of LH and testosterone.

The effects of metformin or orlistat on obese women with polycystic ovary syndrome: a prospective randomized open-label study

PURPOSE

Comparing the effects of metformin or orlistat on hormone, lipid profile and ovulation status in obese women with polycystic ovary syndrome.

METHODS

A total of 80 women were prospectively recruited to receive either metformin (n = 40) or orlistat (n = 40). Weight, BMI, waist, serum LH, total serum testosterone and lipid profile were assessed at baseline and after 3 months. The subjects' ovulatory status was assessed after 3 months.

RESULTS

There was no significant difference in ovulation between the two treatment groups (30% vs 15%). Treatment with either drug showed a significant decline in body weight, BMI (Body Mass Index), and waist circumference, but the degree of decline in both groups was the same. Patients who were treated with orlistat, showed a significant reduction in total testosterone and serum lipid. Women in metformin group showed a significant reduction in serum LH.

CONCLUSIONS

Both metformin and orlistat showed a similar effect on weight loss and ovulation rates.

Treatment of obstructive sleep apnea improves cardiometabolic function in young obese women with polycystic ovary syndrome

CONTEXT

Women with polycystic ovary syndrome (PCOS) are insulin resistant and have a high risk of early-onset diabetes and cardiovascular disease. Obstructive sleep apnea (OSA) has adverse cardiometabolic consequences and is highly prevalent in women with PCOS. We sought to determine whether continuous positive airway pressure (CPAP) treatment of OSA has beneficial effects on cardiometabolic function in PCOS.

METHODS

Laboratory polysomnography and cardiometabolic measurements including insulin sensitivity and secretion (iv glucose tolerance test); 24-h profiles of plasma catecholamines, cortisol, and leptin; and daytime profiles of blood pressure and cardiac autonomic activity (heart rate variability) were obtained at baseline and again after 8 wk of home CPAP treatment with daily usage monitoring.

RESULTS

CPAP treatment modestly improved insulin sensitivity after controlling for body mass index (P = 0.013). The change in insulin sensitivity correlated positively with CPAP use (adjusted P = 0.027) and negatively with body mass index (adjusted P = 0.003). Daytime and nighttime norepinephrine levels were decreased after CPAP (P = 0.002), and the reductions were greater with increased CPAP use (P = 0.03). Epinephrine, cortisol, and leptin levels were not changed significantly. Daytime diastolic blood pressure decreased by an average of 2.3 mm Hg after CPAP (P = 0.035). Cardiac sympathovagal balance was 44% lower (P = 0.007) after CPAP, reflecting a shift toward lower sympathetic activity.

CONCLUSIONS

In young obese women with PCOS, successful treatment of OSA improves insulin sensitivity, decreases sympathetic output, and reduces diastolic blood pressure. The magnitude of these beneficial effects is modulated by the hours of CPAP use and the degree of obesity.

Assessment of cardiovascular risk and prevention of cardiovascular disease in women with the polycystic ovary syndrome: a consensus statement by the Androgen Excess and Polycystic Ovary Syndrome (AE-PCOS) Society

OBJECTIVE

Women with polycystic ovary syndrome (PCOS) often have cardiovascular disease (CVD) risk factors. The Androgen Excess and Polycystic Ovary Syndrome (AE-PCOS) Society created a panel to provide evidence-based reviews of studies assessing PCOS-CVD risk relationships and to develop guidelines for preventing CVD.

PARTICIPANTS

An expert panel in PCOS and CVD reviewed literature and presented recommendations.

EVIDENCE

Only studies comparing PCOS with control patients were included. All electronic databases were searched; reviews included individual studies/databases, systematic reviews, abstracts, and expert data. Articles were excluded if other hyperandrogenic disorders were not excluded, PCOS diagnosis was unclear, controls were not described, or methodology precluded evaluation. Inclusion/exclusion criteria were confirmed by at least two reviewers and arbitrated by a third.

CONSENSUS PROCESS

Systematic reviews of CVD risk factors were compiled and submitted for approval to the AE-PCOS Society Board.

CONCLUSIONS

Women with PCOS with obesity, cigarette smoking, dyslipidemia, hypertension, impaired glucose tolerance, and subclinical vascular disease are at risk, whereas those with metabolic syndrome and/or type 2 diabetes mellitus are at high risk for CVD. Body mass index, waist circumference, serum lipid/glucose, and blood pressure determinations are recommended for all women with PCOS, as is oral glucose tolerance testing in those with obesity, advanced age, personal history of gestational diabetes, or family history of type 2 diabetes mellitus. Mood disorder assessment is suggested in all PCOS patients. Lifestyle management is recommended for primary CVD prevention, targeting low-density and non-high-density lipoprotein cholesterol and adding insulin-sensitizing and other drugs if dyslipidemia or other risk factors persist.

Effects of pioglitazone on menstrual frequency, hyperandrogenism and insulin resistance in adoloscents and young adults with polycystic ovary syndrome

STUDY OBJECTIVE

To study the clinical, metabolic and adverse effects of pioglitazone over a period of 6 months in obese adolescent and young adults with polycystic ovary syndrome.

DESIGN

This was an open labeled study. Each patient served as her own control.

SETTING

Outpatient department of a university affiliated teaching hospital.

PARTICIPANTS

Unmarried women (age 15-25 yrs) with chronic anovulatory cycles and obesity, and with clinical evidence of hyperandrogenism.

INTERVENTIONS

Pioglitazone at a dose of 30 mg once daily for a period of 6 months along with dietary advice and exercise.

MAIN OUTCOME MEASURES

Resumption of normal menstrual cycles, clinical improvement in hyperandrogenism and changes in insulin resistance measured by fasting glucose insulin ratios.

RESULTS

Twenty-two women were enrolled. At the end of the study period 91% of the subjects had regularization of menstrual cycles. There was no change in the modified Ferriman-Gallwey hirsutism scores. Decline in fasting insulin levels at the end of the study was 45.6% from baseline along with significant increase in the fasting glucose/insulin ratio from baseline.

CONCLUSION

Administration of pioglitazone for 6 months along with advice about diet and physical activity in obese adolescents and young adult women with polycystic ovary syndrome results in significant improvements in menstrual frequency. There is a significant improvement in insulin resistance using the G/I ratio (<7.5 mg/10(-4) U) as the biochemical marker.

Evidence-based and potential benefits of metformin in the polycystic ovary syndrome: a comprehensive review

Metformin is an insulin sensitizer widely used for the treatment of patients affected by type 2 diabetes mellitus. Because many women with polycystic ovary syndrome (PCOS) are insulin resistant, metformin was introduced in clinical practice to treat these patients also. Moreover, metformin's effect has other targets beside its insulin-sensitizing action. The present review was aimed at describing all evidence-based and potential uses of metformin in PCOS patients. In particular, we will analyze the uses of metformin not only for the treatment of all PCOS-related disturbances such as menstrual disorders, anovulatory infertility, increased abortion, or complicated pregnancy risk, hyperandrogenism, endometrial, metabolic and cardiovascular abnormalities, but also for the prevention of the syndrome.

An RCT of metformin versus orlistat for the management of obese anovulatory women

BACKGROUND

Treatment of obesity-related anovulation poses a significant clinical challenge. Occasionally, the use of antiobesity medications such as orlistat or insulin sensitizing agents such as metformin is sometimes indicated in these patients. This study aimed to compare the effects of metformin and orlistat for improving ovulation in obese anovulatory women.

METHODS

This was an open-label RCT. A total of 40 women were randomized to receive either metformin (n = 20) or orlistat (n = 20). BMI as well as the androgen profile and the ovulatory status were assessed at baseline and at four weekly intervals for 3 months. Different anthropometric and endocrine parameters were also assessed as possible predictors of ovulation.

RESULTS

There was no significant difference between the two study arms regarding the ovulation rate for metformin and orlistat [40% (n = 8/20) and 25% (n = 5/20), respectively, P = 0.31]. Both arms showed a significant drop in the BMI, testosterone and androstendione concentrations (P < 0.05), but there was no difference between the two arms. Patients who ovulated had significantly lower concentrations of baseline LH, androstendione, dehydroepiandrosterone and free androgen index (P < 0.05). Among these factors, a low baseline LH was found to be the only independent predictor of ovulation (area under curve, 0.85).

CONCLUSIONS

Both metformin and orlistat show a similar effect on weight loss, ovulation rates and androgen concentrations. However, the effects on ovulation rates need to be confirmed in larger studies. The presence of a low baseline serum LH was found to be the most important predictor of ovulation. The study was registered at clinicaltrials.gov. NCT00292799.

Use of insulin-sensitizing agents in the treatment of polycystic ovary syndrome

The role of insulin sensitizing agents is discussed at length in this Committee Opinion.

Case series of rosiglitazone used during the first trimester of pregnancy

Prior to 2007, use of the insulin sensitizer metformin was widely advocated in patients with polycystic ovarian syndrome (PCOS) both to promote ovulation and decrease the incidence of PCOS-associated obstetrical complications. However, the gastrointestinal disturbances associated with metformin led many to discontinue its use. Rosiglitazone is an insulin sensitizer that, because of minimal associated gastrointestinal disturbance, was used as an alternative to metformin in PCOS patients. From 2003 to 2005, 8 women with PCOS unable to tolerate metformin used rosiglitazone for ovulation induction and during their first 12 weeks of gestation. All delivered healthy babies at term, without obstetric complications or congenital anomalies. However, given recent evidence that disputes the reproductive benefits of insulin sensitization for PCOS and that raises safety concerns of rosiglitazone, we are no longer using it for PCOS treatment.

Glucose intolerance in polycystic ovary syndrome--a position statement of the Androgen Excess Society

OBJECTIVES

Women with polycystic ovarian syndrome (PCOS) are at increased risk for developing glucose intolerance and type 2 diabetes mellitus (DM). Recommendations for the timing and method of screening have varied. The purpose of this statement is to determine the optimal screening method, timing of screening, and treatment modalities for impaired glucose tolerance (IGT) among women with PCOS.

PARTICIPANTS

The expert panel was appointed by the Androgen Excess Society (AES) to review the literature and make recommendations based on the available evidence. Meetings were open, and there was no funding for the panel.

EVIDENCE

A systematic review was conducted of the published, peer-reviewed medical literature using MEDLINE to identify studies that addressed the prevalence, risk factors, testing, and treatment for IGT in both adults and adolescents with PCOS. Unpublished data were not considered.

CONSENSUS PROCESS

The panel held meetings to review the literature and draft the statement as a committee. The AES board members reviewed and critiqued the manuscript, and changes were made based on their comments.

CONCLUSIONS

The panel recommends that all patients with PCOS be screened for IGT with a 2-h oral glucose tolerance test. A few members of the AES board recommend alternatively screening women with PCOS for IGT and type 2 DM using an oral glucose tolerance test only in patients with a body mass index of 30 kg/m2 or greater or in lean patients with additional risk factors. Patients with normal glucose tolerance should be rescreened at least once every 2 yr, or more frequently if additional risk factors are identified. Those with IGT should be screened annually for development of type 2 DM. PCOS patients with IGT should be treated with intensive lifestyle modification and weight loss and considered for treatment with insulin-sensitizing agents.

The impact of obesity on female reproductive function

Obesity may be described as the new worldwide epidemic, and its serious impact on morbidity and mortality are well known. As more and more women become obese, the reproductive problems associated with obesity present an ever-growing challenge to physicians involved in their fertility care. The spectrum of reproductive problems associated with obesity encompasses a wide range of disorders including infertility problems, miscarriage and pregnancy complications. In this review, we aim to discuss the impact of obesity on the various aspects of female reproductive function with focus on the clinical aspects of fertility problems in obese women. We finally comment on the available therapeutic options available to this group of women.

Metformin administration is more effective when non-obese patients with polycystic ovary syndrome show both hyperandrogenism and hyperinsulinemia

BACKGROUND

Polycystic ovary syndrome (PCOS) is a common endocrine disease that is frequently observed to be related to increased insulin resistance independent of body weight. The use of insulin-sensitizer compounds, such as metformin, permits great improvement of such metabolic abnormality, restoring ovarian function and gonadal steroid synthesis and reducing insulin resistance.

AIM

On this basis we aimed to evaluate a group of non-obese amenorrheic PCOS patients before and after 6 months of metformin administration (500 mg orally twice daily) to better understand upon which basis of clinical and endocrine parameters metformin administration might be chosen as a putative therapeutic tool.

METHOD

A group of non-obese PCOS patients (n = 42) was enrolled after informed consent. They underwent an oral glucose tolerance test for insulin, glucose and C-peptide levels and provided blood samples for determination of plasma levels of luteinizing hormone (LH), follicle-stimulating hormone, prolactin, estradiol, androstenedione, 17-hydroxyprogesterone, insulin, cortisol and testosterone levels on two occasions: before and on day 7 of the first menstrual cycle occurring after the 5th month of treatment.

RESULTS

Plasma LH, estradiol, insulin and C-peptide were decreased significantly by metformin treatment in the entire group of PCOS patients. When subdividing PCOS patients according to insulin sensitivity (i.e. hyper- and normoinsulinemic subjects), a greater rate of positive endocrine changes was observed in hyperinsulinemic patients and the highest rate was observed in hyperinsulinemic hyperandrogenic subjects. Menstrual cyclicity was recovered in all patients under treatment.

CONCLUSIONS

Our data show that metformin modulates ovarian function and greatly affects LH secretion through reduction of the hyperandrogenic condition. The highest rate of endocrine changes was observed in the hyperinsulinemic hyperandrogenic non-obese PCOS patients. Our study demonstrates that metformin administration is more appropriate in hyperinsulinemic hyperandrogenic non-obese PCOS patients.

Prevalence of polycystic ovarian changes and polycystic ovary syndrome in premenopausal women with treated type 2 diabetes mellitus

OBJECTIVE

To investigate the prevalence of polycystic ovary syndrome (PCOS) and polycystic ovary (PCO) among premenopausal women with type 2 diabetes mellitus (DM).

DESIGN

Case-control study of women with type 2 DM.

SETTING

Tertiary referral university hospital.

PATIENT(S)

Ninety-two premenopausal women with DM, >or=30 years of age, and 20 age- and body mass index-matched healthy premenapousal eumenorrheic women were recruited into the study.

INTERVENTION(S)

An oral glucose tolerance test was performed according to the American Diabetes Association criteria for each healthy woman. After an overnight fasting, blood samples were obtained for the determination of fasting blood glucose, LH, FSH, free T, androstenedione (A(4)), 17-hydroxyprogesterone (17-OHP), DHEAS, PRL, free T(4), TSH, E(2), and sex hormone-binding globulin (SHBG) levels. A GnRH analog (buserelin) test was carried out in 36 patients with DM and PCO (including PCOS subjects), 20 patients with DM without PCO or PCOS, and 20 healthy subjects.

MAIN OUTCOME MEASURE(S)

The prevalence of PCO and PCOS in women with type 2 DM.

RESULT(S)

Fifty-seven (62%) of diabetic patients had normal ovaries, 31 (33.7%) had PCO, and 4 (4.3%) had PCOS. The women with DM (n = 92) and healthy women (n = 20) had similar basal A(4), FSH, E(2), 17-OHP, free T, and DHEAS levels. The LH and SHBG levels were lower and the hirsutism score higher in diabetic patients than in healthy women (P<.05). Peak and area under the curve LH and FSH levels after buserelin testing were significantly higher in healthy women than in the patients (P<.05). Peak A(4) levels after buserelin were significantly higher in the patients than in the healthy women (P<.05). Ovarian volume was significantly greater in the patients with PCO (10.1 +/- 0.7 mL) than in the healthy women (7.0 +/- 0.9 mL) (P<.05).

CONCLUSION(S)

We conclude that PCO but not PCOS is a common finding in premenopausal women with type 2 DM. Suppression of gonadotropins, particularly LH secretion, may play a role in the absence of increased PCOS prevalence among type 2 diabetic patients.

Prevention of diabetes and cardiovascular disease in women with PCOS: treatment with insulin sensitizers

Polycystic ovary syndrome (PCOS) is the most common cause of anovulatory infertility in United States, affecting 6-10% of females in the reproductive age group. Recent studies have shown that insulin resistance plays an important role in the pathogenesis of PCOS. Traditionally, management of PCOS consisted mainly of ovulation induction, treatment of acne and hirsutism, and prevention of endometrial cancer. However, with mounting evidence showing that PCOS is associated with dysmetabolic syndrome and an increased risk for developing diabetes and heart disease, this can no longer be our sole focus. Current data support a strong recommendation that women with PCOS should undergo comprehensive evaluation for diabetes and recognized cardiovascular risk factors and receive appropriate treatment as needed. Lifestyle modifications remain the first-line therapy for all obese women with PCOS. However, many obese women with PCOS find weight loss difficult to achieve and maintain, and this is not an option for lean women with PCOS. For these reasons, insulin-sensitizing drugs are proving to be a promising and unique therapeutic option for chronic treatment of PCOS.

Use of metformin for prevention of ovarian hyperstimulation syndrome: a novel approach

In the present study, which includes 287 participants, metformin has been used by women undergoing IVF/intracytoplasmic sperm injection for more than 5 weeks before and during treatment and during luteal phase. There was no significant difference in number of gonadotrophins used, days of stimulation, number of oocytes retrieved, and number of embryos replaced. There was no significant difference in clinical pregnancy rate between both groups but there was significant reduction in the incidence of ovarian hyperstimulation syndrome (OHSS) in the group taking metformin. Metformin is a safe, cheap drug that can help in prevention of OHSS.

The effects of rosiglitazone and metformin on insulin resistance and serum androgen levels in obese and lean patients with polycystic ovary syndrome

AIM

The aim of this study was to assess the effects of metformin and rosiglitazone on insulin resistance and serum androgen levels in both obese and lean patients with polycystic ovary syndrome (PCOS).

MATERIALS AND METHODS

Forty lean [body mass index (BMI) < 25 kg/m2] and 40 overweight and obese (BMI > 25 kg/m2) patients were included in the study. Waist and hip measurements, serum sex steroid levels, insulin response to 75-g oral glucose tolerance test, fasting insulin, fasting C-peptide levels and homeostasis model assessment of insulin resistance (HOMA-IR) were determined in all patients. The degree of hirsutism was determined by the Ferriman-Gallwey scoring system. Patients were divided into two groups, with 40 (20 overweight and obese; 20 non-obese) patients each. One group was treated with metformin (MET group) 850 mg bid while the other received rosiglitazone (ROSI group) 4 mg/day for 12 weeks. All measurements were repeated at the end of this period.

RESULTS

After the 12-week treatment period, HOMA-IR, area under the curve of insulin, fasting insulin and C-peptide levels were observed to have be decreased significantly in all groups. The decrease in the parameters mentioned above was similar in the four groups. The serum levels of free testosterone, androstenedione and DHEA-S decreased in all groups, but the decrease was statistically significant only in the ROSI groups. Within the lean MET group one patient became pregnant and was hence excluded from the final data analysis. Menstruations became regular after metformin therapy in 41.6% of lean and 35.7% of obese patients who had menstrual disturbance prior to the study. Rosiglitazone therapy improved menstrual disturbance in 61.5 % of lean and 53.8% of obese patients.

CONCLUSIONS

Our data showed that both metformin and rosiglitazone increased insulin sensitivity in obese patients with PCOS as expected, and in lean patients as well. Rosiglitazone seemed to be more effective in decreasing the androgen levels and in achieving slightly greater improvement in menstrual disturbance than metformin.

The effects of rosiglitazone and metformin on menstrual cyclicity and hirsutism in polycystic ovary syndrome

OBJECTIVE

The aim of the present study was to assess the effects of metformin and rosiglitazone on menstrual cyclicity and hirsutism in patients with polycystic ovary syndrome (PCOS).

MATERIALS AND METHODS

Ninety-six patients were included in the study. Serum sex steroids, serum fasting glucose and insulin levels, and insulin response to a 75-g oral glucose tolerance test were assessed in all patients. Menstrual cyclicity, with recording of menses in the 6-month periods before the study and during treatment, was evaluated in each patient. Patients were divided into two groups: one was treated with metformin (MET group, n = 48), while the other received rosiglitazone (ROSI group, n = 48). At baseline and after 24 weeks of treatment all patients underwent hormonal and clinical assessments, including body mass index (BMI), waist and hip measurements and Ferriman - Gallwey (FG) scores.

RESULTS

Of the 96 patients included in the study, 88 (91.7%) were able to complete it and yielded data for analyses. After the 24-week treatment period, fasting insulin levels and area under the curve for serum insulin decreased significantly, while the glucose/insulin ratio increased in both groups. The degree of reduction in serum free testosterone and androstenedione levels was similar in the two groups. The decreases in luteinizing hormone/follicle-stimulating hormone ratio and serum dehydroepiandrosterone sulfate levels were significantly greater in the ROSI group compared with the MET group. BMI increased in the ROSI group, while it decreased in the MET group. In patients with menstrual disturbance treated with rosiglitazone, menstrual cycles became regular in 87.8%, while improvement occurred in 79.3% of the patients treated with metformin. FG score decreased in both ROSI and MET groups, but the degree of decrease was significantly greater in the ROSI group than in the MET group.

CONCLUSION

Our data show that both metformin and rosiglitazone improve ovarian function and hirsutism in patients with PCOS. Rosiglitazone appears better than metformin in the treatment of hirsutism and has better patient tolerance.

The effects of rosiglitazone and metformin on oxidative stress and homocysteine levels in lean patients with polycystic ovary syndrome

BACKGROUND

Oxidative stress and hyperhomocysteinaemia are risk factors for cardiovascular diseases. The aim of this study was to assess the effects of rosiglitazone and metformin on cardiovascular disease risk factors such as insulin resistance, oxidative stress and homocysteine levels in lean patients with polycystic ovary syndrome (PCOS).

METHODS

Fifty lean patients (BMI <25 kg/m2) with PCOS and 35 healthy subjects were included this study. Serum homocysteine, sex steroids, fasting insulin, fasting glucose and lipid levels were measured. Total antioxidant status (TAS; combines concentrations of individual antioxidants) and malonyldialdehyde concentration (MDA) were determined. Insulin resistance was evaluated by using the homeostasis model insulin resistance index (HOMA-IR), quantitative insulin sensitivity check index (QUICKI), Area under the curve insulin (AUCI) and the insulin sensitivity index (ISI). Patients were divided into two groups. One group was treated with metformin (n = 25) and the other received rosiglitazone (n = 25) for 12 weeks. All measurements were repeated at the end of 12 weeks.

RESULTS

Compared with healthy women, those with PCOS had significantly elevated serum MDA, homocysteine, HOMA-IR, AUCI and lipoprotein a levels, and significantly decreased serum TAS, QUICKI and ISI. Serum free testosterone levels showed a significant positive correlation with MDA, AUCI and HOMA-IR, and a negative correlation with TAS, ISI and QUICKI in PCOS patients. HOMA-IR and AUCI significantly decreased, while QUICKI and ISI significantly increased after treatment in both groups. Serum TAS level increased and serum MDA level decreased after the rosiglitazone treatment, but these parameters did not change after the metformin treatment. Serum homocysteine and lipid levels did not change in either group, while serum androgen levels and LH/FSH ratio significantly decreased after the treatment period in only the rosiglitazone-treated group.

CONCLUSION

Elevated insulin resistance, oxidative stress and plasma homocysteine levels and changes in serum lipid profile (risk factors for cardiovascular disease) were observed in lean PCOS patients. Rosiglitazone seemed to decrease elevated oxidative stress when compared with metformin treatment in lean PCOS patients.

Is ovulation induction still a therapeutic problem in patients with polycystic ovary syndrome?

Polycystic ovary syndrome (PCOS) is one of the most common endocrine diseases affecting women of fertile age, and is characterized by hyperandrogenism, chronic anovulatory cycles and oligomenorrhea or amenorrhea. Given the repercussions of chronic anovulation on sterility, PCOS is a heavy social burden. Here we describe the procedures used to induce ovulation in PCOS patients, the surgical approach and medical treatments that are still being experimented.

The effects of metformin on insulin resistance, clomiphene-induced ovulation and pregnancy rates in women with polycystic ovary syndrome

OBJECTIVE(S)

To evaluate the effects of metformin on insulin resistance, ovarian androgen production, and clomiphene-induced ovulation and pregnancy rates in infertile women with polycystic ovary syndrome (PCOS).

STUDY DESIGN

Twenty-one infertile women with PCOS were selected in this prospective randomized clinical study. Basal steroid and gonadotropin levels were measured, and oral glucose tolerance test (OGTT) was performed. The patients were divided randomly into group 1 (n = 11) and group 2 (n = 10). Group 1 patients were treated with 1700 mg per day of metformin for 3 months. The basal tests and OGTT were repeated after metformin therapy. Group 2 patients did not receive metformin. The patients in both groups received 100 mg of clomiphene citrate (CC) daily for 5 days until either a pregnancy occurred, or six CC cycles were reached. Metformin administration continued during CC therapy until the day of hCG in group 1. Serum progesterone (P) level >or=5 ng/ml was considered as confirmatory of ovulation. Ovulation and pregnancy rates after six cycles were determined.

RESULTS

Serum androgens and insulin response to OGTT decreased significantly after metformin therapy. Midluteal serum P level was significantly higher in cycles treated with metformin plus CC (P < 0.05). The ovulation (38 of 51 cycles, 74.4% versus 34 of 55 cycles, 61.8%) and pregnancy rates (5 of 11 women, 45.5% versus 3 of 10 women, 30%) were higher, but not significantly, in the metformin plus CC group than in the CC alone group. All the patients who conceived had insulin resistance in group 1 whereas non-insulin resistance in group 2.

CONCLUSION(S)

Metformin improves insulin resistance and reduces androgen levels. Metformin did not increase significantly the ovulation and pregnancy rates.

Exaggerated 17-hydroxyprogesterone response to intravenous infusions of recombinant human LH in women with polycystic ovary syndrome

Studies using pharmacological gonadotropin stimulation suggest that ovarian steroidogenesis is abnormal in the polycystic ovary syndrome (PCOS). We assessed ovarian steroid secretion in response to near-physiological gonadotropin stimuli in 12 ovulatory controls and 7 women with PCOS. A gonadotropin-releasing hormone-receptor antagonist (ganirelix, 2 mg sc) was given to block endogenous LH secretion, followed by dexamethasone (0.75 mg orally) to suppress adrenal androgen secretion. After ganirelix injection (12 h), intravenous infusions of recombinant human LH (0, 10, 30, 100, and 300 IU; each over 8 min) were administered at 4-h intervals in a pseudorandomized (highest dose last) manner. Plasma LH, 17-hydroxyprogesterone (17-OHP), androstenedione, and testosterone were measured concurrently. LH dose-steroid response relationships (mean sex-steroid concentration vs. mean LH concentration over 4 h postinfusion) were examined for each subject. Linear regression of 17-OHP on LH yielded a higher (mean +/- SE) slope in PCOS (0.028 +/- 0.010 vs. 0.005 +/- 0.005, P < 0.05), whereas extrapolated 17-OHP at zero LH was similar. The slopes of other regressions did not differ from zero in either PCOS or controls. We conclude that near-physiological LH stimulation drives heightened 17-OHP secretion in patients with PCOS, suggesting abnormalities of early steps of ovarian steroidogenesis. With the exception of 17-OHP response in PCOS, no acute LH dose-ovarian steroid responses were observed in controls or PCOS. Defining the precise mechanistic basis of heightened precursor responsiveness to LH in PCOS will require further clinical investigation.

Polycystic ovarian syndrome: diagnosis and management

Polycystic ovarian syndrome (PCOS) affects 4% to 12% of women of reproductive age. The lack of well-defined diagnostic criteria makes identification of this common disease confusing to many clinicians. Also, with the varied manifestations of the disorder a patient may present to any one of several providers: an internist, family practitioner, nurse practitioner, pediatrician, gynecologist, dermatologist, or endocrinologist. Furthermore, the most distressing aspect of PCOS for any given patient may change over time, from hirsutism as a teenager to infertility as a young adult--potentially requiring several different providers along the way. It is important, therefore, that those caring for these patients understand not only the management issues pertinent to their specialty, but also appreciate the other potential health risks in these women. Recent insights into the pathophysiology of PCOS have shown insulin resistance to play a substantial role and as such have brought the long-term issues of type 2 diabetes mellitus and its resultant increased risk of coronary artery disease to the forefront. No longer can irregular menses and/or hirsutism be thought of as benign nuisances. This review will focus on the two most confusing aspects of PCOS for the practicing provider--diagnosis/differential diagnosis and treatment options. Special attention is given to the role of insulin resistance and the potential utility of insulin sensitizers in management. The benefit and utmost importance of lifestyle modification for the long-term health of these women is stressed as well. It is hoped that some clarity in this regard will allow more women to not only be diagnosed and managed properly for their presenting symptoms (hirsutism, irregular menses, etc.), but also to be educated and managed for the continuing health risk of insulin resistance throughout their lives.

Treatment of PCOS with metformin and other insulin-sensitizing agents

A significant proportion of women with polycystic ovary syndrome (PCOS) suffer from insulin resistance and compensatory hyperinsulinemia. Growing evidence indicates that elevated serum insulin induces hyperandrogenism, which in turn leads to anovulation and infertility. Hyperinsulinemia also contributes to the increased risk for cardiovascular disorders and type 2 diabetes mellitus. These concepts provide a rationale for therapies focused on treatments of insulin resistance. Metformin is the most extensively studied insulin-sensitizing agent for the treatment of women with PCOS. Use of metformin leads to a decrease in serum insulin and androgen levels, as well as an improvement in ovulatory function. Other insulin-sensitizing agents studied in women with PCOS include troglitazone, rosiglitazone, pioglitazone, and D-chiro-inositol.

Conservative management of gynecologic diseases: insulin sensitizing agents in polycystic ovary syndrome

A contemporary "Pandora's box" could be the polycystic ovary syndrome (PCOS), containing several negative features for a woman: compromised looks, compromised fertility; increased metabolic risk factors; and compromised general health. During the past decade, the central importance of insulin resistance (IR) in the pathogenesis of this syndrome has been established. Several in vivo and in vitro studies have demonstrated this phenomenon, initially by the hyperinsulinemic response to oral glucose in obese and lean women with PCOS compared with weight-matched normal women, and subsequently with more sensitive techniques like euglycemic hyperinsulinemic clamp. In vitro studies have corroborated these findings, showing molecular defects at the postreceptor level of insulin action, such as increased serine phosphorylation and decreased phosphoinositol 3-kinase action. Insulin sensitizers are the group of therapeutic agents that hold some promise of helping women with polycystic ovary syndrome (PCOS), since the role of insulin resistance and hyperinsulinemia appear to be major contributors to the pathophysiology of the syndrome. The therapeutic approach with insulin sensitizers appears to have beneficial effects on the metabolic as well as on the reproductive abnormalities in women affected by PCOS. Finally, insulin sensitizers should be considered by all subspecialists who aim at a comprehensive management of patients with PCOS.

Medical treatment regimens of hirsutism

Hirsutism, which is a common clinical problem in women of reproductive age, is characterized by excessive growth of terminal hair in the androgen-sensitive skin regions. It is the result of either androgen excess or increased sensitivity of the hair follicles to normal levels of androgens. The management, which includes cosmetic measures and medical treatment, is far from satisfactory. Anti-androgen drugs play a key role in the treatment of hirsutism, but they have some side-effects which may result in cessation of the drug. On the other hand, anti-androgen treatment often needs to be continued for a long time. So, safe, inexpensive, and effective anti-androgen drugs are needed. Recently low-dose anti-androgen drugs have been shown to be effective in the maintenance of treatment. On the other hand, cyproterone acetate plus ethyniloestradiol and spironolactone, cyproterone acetate plus ethyniloestradiol and finasteride, and spironolactone and finasteride combinations have been used successfully in decreasing the hirsutism score. There are also some promising data regarding the effects of insulin sensitizers in the treatment of hirsutism, particularly in patients with polycystic ovarian syndrome. In the present review, the main features of anti-androgen drugs, new combined treatments, and insulin sensitizers in the treatment of hirsutism are discussed.

Effects of short-term metformin treatment on insulin sensitivity of blood glucose and free fatty acids

AIM

Based on the known effect of metformin (MET) in improving insulin sensitivity in type 2 diabetes, with the scope to focus the effects on glycaemic and free fatty acids (FFA) levels, we studied the effects of a short-term treatment with this drug in obese subjects and obese patients with diabetes or family history of diabetes (FHD). We used a method to allow us to evaluate the possible difference of insulin sensibility with regard to the insulin action on glycaemia and blood FFA, both in the basal state and during oral glucose tolerance test (OGTT).

METHODS

Insulin sensitivity was investigated before and after MET treatment (850 mg bid for 10 days) in seven obese subjects with normal glucose tolerance and without FHD and 13 obese patients with diabetes (n=7) or FHD (n=6). By using specifically designed formulae, we calculated four insulin-sensitivity indices (ISI) from basal level (b) and area values (a) (during OGTT) of insulinaemia, glycaemia (gly) or FFA (ffa), namely: ISI (gly)-b, ISI (gly)-a, ISI (ffa)-b and ISI (ffa)-a.

RESULTS

In patients with diabetes or FHD, MET improved ISI (gly)-b (0.79 +/- 0.06 vs. 0.59 +/- 0.07, p<0.001) and ISI (gly)-a (0.69 +/- 0.09 vs. 0.51 +/- 0.07, p<0.05), whereas only minor changes occurred for ISI (ffa)-b and ISI (ffa)-a. In contrast, in simple obese subjects, MET induced further deterioration of both ISI (gly)-a (0.47 +/- 0.07 vs. 0.64 +/- 0.10, p<0.01) and ISI (ffa)-a (0.43 +/- 0.07 vs. 0.55 +/- 0.08, p<0.05). Fasting level and total area of lactate were high in the obese patients and were not affected by MET. A statistically significant increase (p<0.01), however, was observed for the 'decremental' area of lactate in obese subjects with diabetes or FHD, which might probably contribute to the reduction of insulin resistance induced by the drug in these patients.

CONCLUSIONS

Although the low number of subjects studied precludes absolute conclusions, data would suggest that MET improved ISI towards glucose but not towards FFA, in the diabetic and 'prediabetic' obese patients, whereas worsened it in the obese subjects without FHD. Therefore, the effects of MET would not be secondary to changes of FFA but rather to a primary action of MET on glucose metabolism. Thus, utilization of MET to treat the insulin resistance in obesity is indicated only in the presence of alterations of glucose metabolism or FHD.

The role of metformin in the management of polycystic ovary syndrome

PURPOSE OF REVIEW

The purpose of this review is to provide a critical summary of recent studies on the clinical effects of metformin in polycystic ovary syndrome.

RECENT FINDINGS

After the recognition that hyperinsulinaemia is a fundamental disturbance in polycystic ovary syndrome, a novel and promising form of therapy in the form of insulin-sensitizing drugs has been introduced. Among these, metformin is the most widely used. This therapeutic intervention has been shown to exert beneficial effects on the endocrine and metabolic disturbances that characterize the syndrome and, more recently, to improve the reproductive outcome in women with polycystic ovary syndrome. With rapid progress in this area, metformin use has also been extended to the management of lean polycystic ovary syndrome patients.

SUMMARY

Although most studies are nonrandomized trials, current data provide a rationale for metformin as first-line management for women with polycystic ovary syndrome, alone or in combination with conventional treatments. Controversy still exists, however, regarding the mechanisms by which metformin exerts its beneficial effects in polycystic ovary syndrome.

Obese patients with polycystic ovary syndrome: evidence that metformin does not restore sensitivity of the gonadotropin-releasing hormone pulse generator to inhibition by ovarian steroids

Women with polycystic ovary syndrome (PCOS) have reduced GnRH sensitivity to suppression by ovarian steroids, which can be ameliorated by androgen blockade. We studied nine PCOS women and nine controls to determine whether metformin could change feedback inhibition by estradiol (E(2)) and progesterone (P). LH was measured every 10 min, and FSH, E(2), P, and testosterone (T) were measured every 2 h. Frequently sampled iv glucose tolerance test was performed at the end of each admission. After the first admission, metformin (500 mg, three times a day) was started. The second admission occurred on d 8-11 of the next menstrual cycle in controls and on d 28 in PCOS patients. Patients subsequently took E(2) and P for 1 wk until the third admission. At baseline, PCOS women had higher T, free T, androstenedione, and estrone. After 4 wk of metformin, controls had a slight reduction in total T, but free T was unchanged. However, PCOS patients had reduced insulin, T, and E(2), and increased LH mean/amplitude and FSH. After ovarian steroids, controls had a greater reduction in LH pulse frequency than PCOS (61 vs. 25%). These results suggest that the beneficial effects of metformin on ovulatory function in obese PCOS women are probably not mediated by enhanced hypothalamic sensitivity.

Insulin-lowering agents in the management of polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a medical condition that has brought multiple specialists together. Gynecologists, endocrinologists, cardiologists, pediatricians, and dermatologists are all concerned with PCOS patients and share research data and design clinical trials to learn more about the syndrome. Insulin resistance is a common feature of PCOS and is more marked in obese women, suggesting that PCOS and obesity have a synergistic effect on the magnitude of the insulin disorder. Hyperinsulinemia associated with insulin resistance has been causally linked to all features of the syndrome, such as hyperandrogenism, reproductive disorders, acne, hirsutism, and metabolic disturbances. Women with PCOS should be evaluated for cardiovascular risk factors, such as lipid profile and blood pressure. Modification of diet and lifestyle should be suggested to those who are obese. Several insulin-lowering agents have been tested in the management of PCOS. In particular, metformin is the only drug currently in widespread clinical use for treatment of PCOS. In a high percentage of patients, treatment with metformin is followed by regularization of menstrual cycle, reduction in hyperandrogenism and in cardiovascular risk factors, and improvement in response to therapies for induction of ovulation.

Effects of metformin on body mass index, menstrual cyclicity, and ovulation induction in women with polycystic ovary syndrome

OBJECTIVE

Metformin has been used as a treatment in many studies of the infertility associated with polycystic ovary syndrome (PCOS). We will review the literature on this topic as it specifically relates to changes in body mass index (BMI), improvement in menstrual cyclicity, and effects on ovulation and pregnancy rates.

DESIGN

Review of studies addressing biochemical and clinical changes in women with PCOS on metformin.

MAIN OUTCOME MEASURE(S)

Changes in BMI, menstrual cyclicity, ovulation rate, and pregnancy rate.

RESULT(S)

Metformin has been shown to produce small but significant reductions in BMI. Multiple observational studies have confirmed an improvement in menstrual cyclicity with metformin therapy. The studies addressing the concomitant use of metformin with clomiphene citrate initially predicted great success, but these have been followed by more modest results. There is little data in the literature concerning the use of metformin and hMGs.

CONCLUSION(S)

Some (but not all) women with PCOS have improvements in their menstrual cycles while on metformin. The data supporting the use of metformin in ovulation induction with clomiphene citrate and hMG remain to be confirmed by large, randomized, prospective studies.